Ponant newbuild chief details what it takes to Swap2Zero

By 2030, Ponant aims to deliver a ship designed for zero CO2 equivalent emissions, taking into account CO2, methane and nitrogen oxides. Its Swap2Zero concept stands for 'sustainable wind-assisted propulsion, zero emission ready.'

Newbuilding and R&D Director Petiteau and his team have designed a 181-meter/594-foot sailing vessel with approximately 100 staterooms that would be able to operate with at least one month autonomy.

Multi-energy approach

To do this, Ponant envisions a multi-energy approach.

Ponant is considering two sail systems, Ayro Oceanwings, left, and Solid Sail

Besides sails — Ayro Oceanwings and Solid Sail systems are under consideration — the ship would use green hydrogen-powered fuel cells for propulsion when there's no wind.

Petiteau explained the hotel needs can't be met by hydrogen because it takes a lot of space, and nobody knows if it will be available at scale in six or seven years, or the cost. Power for the hotel load would come from solid oxide fuel cells using biomethane.

Methane contains a carbon molecule that would be captured, leaving the hydrogen to use for electricity. The captured carbon would be liquefied and stored on board for discharge ashore. As part of the circular economy, this biogenic carbon can be used with green hydrogen to produce synthetic fuel.

'It is quite challenging but we are studying all solutions we could develop for that,' Petiteau said, adding the project is generating great enthusiasm from many potential partners with different solutions and equipment.

Bold plan

Most cruise operators are looking at ways to decarbonize and taking risks to test new technologies. Petiteau praised those initiatives but said Ponant is going further, faster.

'Other companies are trying to integrate hydrogen and that's a good thing because we show energy providers we are interested in buying new energy. It's better to be in a group, pushing. MSC is looking at integrating hydrogen and that's a good thing. Accor is using sails and that's a good thing, and it pushes the industry forward,' he said.

But unlike those looking at reducing CO2 emissions by 20% or 30% now, Ponant's aiming to build a vessel soon to comply with the rules that will be in force in 20 or 30 years, 'so the target is not the same.'

It is a bold plan, especially for a small company like Ponant.

Petiteau said it's always been in Ponant's spirit to innovate and look for ways to reduce its environmental footprint, pointing out the company was founded by sailors and its first ship was a sailing vessel. Since then the dream was to build a bigger sailing ship but the technology didn't exist.

Ponant had looked at putting sails on Le Boréal class but that would not have worked; it would have made the ships heavier, less efficient and less stable.

'If you want a sailing ship, you have to completely rethink the architecture of the vessel,' Petiteau said.

The hull would have to be different and the vessel's length would depend on the thrust capacity of the sails. Even the accommodation arrangement must be different because of the mast and the sails.

Today companies are investing to invent new equipment like sails, fuel cells and hydrogen storage systems. And Ponant has learned by innovating with its Explorer-class vessels and Le Commandant Charcot, an icebreaker cruise ship that reaches the North Pole using LNG and batteries.

Le Commandant Charcot

A small ship is key to achieving net zero carbon because it doesn't require a lot of power. Ponant's concept needs 1.5 or 2 MW for propulsion and the same amount for the hotel load. This allows the testing of technologies that can then scale up for bigger ships.

Background

Petiteau, who worked seven years at Chantiers de l'Atlantique, took charge of Ponant's newbuilding department in 2015 and assembled an in-house R&D team with the goal of finding ways to decarbonize the fleet after the 2021 introduction of Le Commandant Charcot.

It took a year just to understand the upcoming regulation, the technologies and fuels that could be used for retrofitting and to get a grasp of the changing regulations. Now the IMO's Carbon Intensity Index and the EU's Emissions Trading Scheme have come into force so it's clear shipping has to reach net zero carbon by 2050. 

Ponant built its own decarbonization road map, setting the milestones of a 15% reduction in CO2 emissions by 2026, 30% by 2030 and 80% by 2040 'because we need to be a bit earlier than the rules, otherwise we will be late,' Petiteau said.

To reach the 2026 and 2030 targets, Ponant will retrofit vessels to improve the hull and engine efficiency, reduce propulsion power/speed and upgrade on-board systems to save energy. Energy audits using a digital twin at Chantiers de l'Atlantique help understand what could be achieved.

With all these efforts, a 20% reduction in carbon emissions looked possible but to go further, a new type of fuel is needed. Ponant has tested B100, which appears to cut CO2 emissions 90%.

But biofuel isn't widely available, and it's really expensive.

'So we started to think which kind of vessel should we build close to 2030?' Petiteau said. Since cruise ships typically have at least a 30-year lifespan, it will be 20 years old in 2050 and still have a decade or more in service.

Starting with a technical — not commercial — approach

The R&D team decided to begin from the technical standpoint — not the usual commercial approach that starts with the type of product desired, number of berths and deployment.

After imagining a concept that could come into service in six or seven years with net zero carbon, then they would tackle how to change the economic model to demonstrate if a net zero carbon cruise ship is commercially feasible.

'Today passengers don't select a cruise because this one has less CO2 emssions than others,' Petiteau noted. 'But tomorrow will be very different. The consciousness is changing very fast. We believe that we need to take that direction now, otherwise the full cruise industry may be in danger.'

Three pillars

The three technical pillars for Ponant's newbuild design are optimization, energy conservation and efficiency.

Optimization — To use renewable energy, it must be a sailing ship. The size is determined by the sail power of the systems that are just starting to be built today. And the design not just a hull with masts; it must be optimized for the sailing system.

Energy conservation  — How to use less energy on board, starting from basics like shutting off the lights in unoccupied rooms, improving the vessel's thermal insulation and myriad other measures.

Energy efficiency — The Ponant ship will be built for a 10-knot operating speed so the hull will be designed for this. Traditionally, ships are built for maximum speed 'but it is nonsense because you never operate the vessel at maximum speed,' Petiteau said. 'We will push the yard to think differently and optimize the vessel for the speed we really need and in this way we will save a lot of energy.'

Ten knots may sound slow for a cruise ship but this is a sailing vessel, and Ponant's aim is for the wind to contribute up to 50% of the propulsion power. The sails won't be useful if the ship operates faster than 10 knots.

That's because the sails' thrust contribution depends on the apparent wind force and direction. If the vessel speed increases too much, the apparent wind direction will get close to a headwind. The sails' thrust will drastically drop to zero.

Slow cruising

All of this means a different type of cruise, marketed in a different way.

'The project is complex technically but also commercially because we want to give passengers something that is aligned with the technical ambition,' Petiteau explained. 'We still want to have a luxury product, something comfortable.

'... We want to promote a slow cruise, to take time — not run to the next port, everybody on board at 6 p.m. because we have to rush. No. People are there to enjoy, to rest. We want to offer a new type of cruise that corresponds to this vessel's spirit.'

Deployment

The R&D team's work involves studying wind statistics to know where the ship might operate. A model has been tested in several scenarios to understand the wind force needed, and that's the basis for deciding the deployment.

Currently one scenario has the ship operating in northern Europe, south of Norway, in the British Isles and along the French coast for five to six months a year, then crossing the Atlantic with the trade winds for six months in the Caribbean.

Petiteau said the Mediterranean is difficult because 'either you have too much wind or no wind.'

Some concepts can operate carbon-emission-free for short stints of two or three days, or in coastal service. Ponant has a much steeper goal of one month. The size of the fuel tanks and the power range accounts for the possibility of at least 15 days with no wind.

Solid waste and wastewater

Ponant isn't just focused on air emissions. It's addressing solid waste and wastewater.

'We believe all the waste on board can be changed into something valuable, into energy or into something that can be recyled,' Petiteau said, creating a circular economy.

Used oil will be offloaded to companies that can transform it into biofuel. And, via hydrothermal carbonization, food waste and biowaste from toilets will go into producing biochar, which can be used for  fertilizer and, potentially, carbon sequestration.

Treatments to remove nano-plastics are another focus, to avoid discharging plastic particles into the water.

Interior design

Ponant has signed on to the Sustainable Maritime Interiors Commitment and Declaration that aims to reduce the carbon footprint of interior architecture. The line will be inviting architects to submit proposals and solutions.

The one selected for the ship's interiors will be challenged to reduce the carbon footprint of the accommodations by using all recycled materials, or more durable ones. For example, instead of carpet that has to be replaced every five years, it should last 10 years.

Also, the design should incorporate furniture and equipment that can be repaired on board instead of having to truck it to a factory.

Reducing the carbon footprint during construction

'We have a holistic approach,' Petiteau said. So, beyond just focusing on the ship's operation, Ponant also plans to reduce the carbon footprint during construction.

To do this, it will use recycled materials such as 100% recycled steel for the hull, produced locally using green electricity.

Opportunity to participate and learn

Petiteau said Swap2Zero offers equipment suppliers, shipyards, classification societies and flag states the opportunity to 'work on a real concept ... to apply the new regulations to check if the regulations are fit ...'

Everybody will contribute, and everybody will learn, he said: 'Because there are many, many things we do not know and we will all learn together, it will be easier for the marine industry to implement the system. It is a way to participate in the eco-energetic transition of the maritime industry.'

Ponant isn't ready to talk about partners because their selection is ongoing.

They're being assessed to determine such advantages as which has better efficiency or will be certified by a classification society or presents the lowest footprint or weight. Many things have to be compared, and Ponant is in the benchmarking phase for the fuel cell, sails, propulsion and power management.

Some months ago the company issued a tender specification to European shipyards and is close to selecting one to work toward a contract.

'We want the vessel to be built in Europe with European equipment,' Petiteau said. 'The solar panels, for example, should not be built in China. They should be built in Europe with the lowest carbon footprint.'

Many of the potential partners are French, thanks to the industrial clusters around Saint-Nazaire and Marseille, where Petiteau's team is located.

'There are many, many French players for the sails, the hydrogen and the power management system. We're also in discussion with European partners,' he said, as with Le Commandant Charcot. (That ship was built by Fincantieri's Vard facilities in Tulcea, Romania and Søviknes, Norway.)

For the sails, Ponant already narrowed its choices to SolidSail and Ayro Ocean Wings, both French concepts. They made the cut because they have sailing systems at scale, and sails that can be lowered. That's vital for a passenger ship, which is subject to strict stability rules.

In comparing SolidSail and Ayro Ocean Wings, Ponant is looking at many factors including the thrust (the power provided by the sails), the weight of the equipment, the impact on stability, the cost and how to integrate the technology.

Seeking support from the French government and the EU

Government support

It's costly to be the first. Ponant seeks partners willing to shoulder the risks along with it and is applying for support from the French government and the European Union.

And as time goes by, there will be more suppliers of components like fuel cells and prices will go down.

'You have to have a vision, look at the 30 years' lifetime of the vessel,' Petiteau said. 'If you look at three years, the project is too costly ... But if you think about 10 or 20 years of operation, looking at the fact the fuel cost will increase a lot and you will have to pay tax that will be more and more expensive for each single ton of CO2 [emitted].

'We have made this analysis and demonstrated that having this long-term vision will be more interesting financially speaking than to just consider using biofuel or synthetic fuel.

Some cruise operators may decide to pay the progressive carbon tax no matter what. 'The risks are huge and the horizon is so obscure that some are just waiting. We don't want to be like that,' Petiteau said. 'We want to be proactive and to contribute to a solution.'

What will it cost to cruise on such a ship?

'We don't know yet,' Petiteau said. 'Today customers are willing to pay just a little bit more for reduced carbon emissions. But tomorrow, I think things will change.'